Hi all,
My brand-new focusrite itrack dock (made in May 2015) makes this weird hardware sound- think screeching fire alarm (that bleeds into auria as well) when it is fully charged at 100%. The only way to stop this is to drain the battery a little, and max out the brightness while using it so that I can prolong the charge time before the screeching comes back. Does anyone else have this problem, and do you have any fixes to share? I've emailed focusrite support in the meantime, and am currently waiting for them to get back to me.

Thanks Rim, I have emailed Focusrite, and they've suggested that I try to see if this happens with another iPad, and asked if I was using something other than the factory supplied power adaptor (I'm not).

Gonna try it out when I get home tonight, albeit with an iPad 3 and not another iPad Air 2...

so I've made a video and this is what it sounds like....
It's ridiculous how it can be heard from hardware and software, but I'm having difficulty at the moment convincing my retail shop that this is a problem, and that the itrack dock shouldn't be doing this.

Rim wrote:I couldn't hear any noise in your video. At what time does it start?

Rim

It's about 20 seconds in. If you hear something that sounds like a reversing truck, that's it. (It's worse when you hear it in the headphones because the hardware sounds bleed into the headphone out and hence, starts sounding like a screech)

Note that the noise is coming from the itrack dock itself, no speakers connected, and headphone output at zero. The initial bit is to show when the sounds starts occurring, because the iPad has to be fully charged or it won't occur.

So after much pain, the retail shop sent me another Focusrite itrack dock, which was helpful.

Unfortunately I can't tell whether the issue is hardware or software (Auria pro). I had originally thought that it was the Focusrite itrack dock only because of the hardware pulsing, but my current hypothesis is that it could an incompatible (and bizarre) interaction of both.

Basically I've done the following on my iPad Air 2 iOS 9.3.1, and this is what I've observed with the new itrack dock:
(Before making the following observations, I deleted Auria pro, reinstalled it, closed all other programs and did a hard reset)

So what would modify/affect this behaviour?
1) adjusting the brightness of the iPad alters the pitch of the pulsing screech
2) this pulsing screech (hardware and software) does not occur in any other apps except Auria pro (I've tried switching over to GarageBand, animoog, bias amp, etc.
3) the pulsing screech (hardware and software) pulses with the CPU meter in Auria pro
4) no pulsing screech (hardware and software) as long as battery is not near 98%, so working in Auria pro is fine until then

I also was able to try the itrack dock with an iPad 3, iOS 9.3.1, with a fresh install of Auria pro.
1) there was no pulsing screech from the hardware, however, there was slight pulsing (much much much quieter (and bearable) than the iPad Air 2) that could be heard on the itrack headphone out, when the iPad 3's battery hit 100%. Again, no pulsing when switching over to GarageBand.

Rim, from the Auria side of things, is this an Auria pro bug, or a hardware incompatibility with the Focusrite itrack dock itself? Happy to work this out with you (via pm as well, if more appropriate) as this info will assist me in deciding whether to return the dock or not.

I've got to say, this is one unusual issue. Auria (and all iOS apps for that matter) have no way to control the audio hardware. iOS does all that for you, so if an interface works in one app, it'll work in all apps. Apple doesn't allow developers low level access to the audio hardware, so essentially, iOS just sends audio directly to Auria and grabs audio from Auria, and that's where it ends. So there's nothing I can think of that would cause what you're describing. And the fact that it changes with the brightness of the backlight, or the batter power tells me that it's a hardware issue, no doubt about it.

I suspect this might be an issue with your headphones. If there was a problem with the ground connection, I could see EMI or RFI causing noise like you describe. Can you try another pair of headphones? What kind of headphones are you testing with now? Also, it might be an issue with your iPad's headphone jack as well.

Another thought, is there could be a power noise issue. Can you try plugging the iTrack Dock into another AC outlet? When they replaced the iTrack, did they replace the power adapter? Try using a new power adapter, as that could be defective and causing DC/DC switching noise.

Rim wrote:And the fact that it changes with the brightness of the backlight, or the batter power tells me that it's a hardware issue, no doubt about it.

The issue is weird, alright... Thanks for your explanation, but I'm not so sure that this is a hardware issue only. The thing about this is we also need to separate the screeching pulse in two variants-
1) produced from hardware itself
2) produced from headphone output of itrack dock which goes through software

In 1), when the iPad is 98%-100% charged, the screeching pulse will occur, regardless of whatever app is running. The pulse in this instance is not affected by changing screen brightness.

In 2), when the iPad is 98-100% charged, the screeching pulse will occur, only in auria pro. Although the pulse is still heard from 1) (like in the video above), the screeching pulse will only occur in auria pro, and not in GarageBand, bias, etc. In 2), when I plug in my headphones direct to the iPad's headphone output, no screeching pulse is heard through my headphones, but the pulsing will continue being emitted from the hardware itself.

Here's the thing, if this issue is hardware only, then why am I having difficulty reproducing the issue in other apps?

Rim wrote:I suspect this might be an issue with your headphones. If there was a problem with the ground connection, I could see EMI or RFI causing noise like you describe. Can you try another pair of headphones? What kind of headphones are you testing with now? Also, it might be an issue with your iPad's headphone jack as well.

So far, I've been using two different earbuds, with a 1/4 inch adapter. I'm currently charging my iPad up to 100% before trying to see if I can replicate the issue with 1) another 1/4 inch adapter, and 2) another set of headphones- my sennheiser hd280 pros with its own adapter.

Rim wrote:
Another thought, is there could be a power noise issue. Can you try plugging the iTrack Dock into another AC outlet? When they replaced the iTrack, did they replace the power adapter? Try using a new power adapter, as that could be defective and causing DC/DC switching noise.

I've plugged the itrack dock in different rooms, same issue. When the new itrack dock was sent to me, it also came with a new power adapter- that's the one I'm currently using.

Untilted wrote:
So far, I've been using two different earbuds, with a 1/4 inch adapter. I'm currently charging my iPad up to 100% before trying to see if I can replicate the issue with 1) another 1/4 inch adapter, and 2) another set of headphones- my sennheiser hd280 pros with its own adapter.

Update: I've been able to replicate the same issue across different earbuds/ headphones and 1/4 inch Jack adapters, so unlikely to be an issue with my earbuds/ headphones, I believe.